Telephone instrument base



FIG. 1 is front, top and right side perspective view of a telephone instrument base showing our new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof, the side opposite being substantially a mirror image; and

FIG. 4 is a bottom plan view thereof. 

The ornamental design for telephone instrument base, as shown and described. 